Ultimogeniture is a succession law where the youngest child (based on gender law) inherits all titles.
Availability
- Easily accessible as only Limited crown authority is required. With the
Conclave DLC activated, it requires Late Feudal Administration. - Used by Mongol hordes if
Horse Lords is inactive; with Horse Lords activated, Mongol hordes are nomadic and use nomadic succession. - One of the few succession laws available to Eastern religions.
- Unavailable to West African paganism.
Advantages and disadvantages
- A regency and civil wars are common, as the heir often is under-aged. The trade-off is higher chances of long and stable reigns, and vassal opinion boosts because of it.
- Arguably better than primogeniture, as the player can stop having children once they get a desired heir.
- Succession at young age shifts more control over from AI to you. You are much less likely to suddenly end up in control of an excommunicated maimed kin-slaying drunkard of a heretical religion. (Because the AI wasn't given the time to make one for you)
- All the direct advantages of a long reign. Such as:
- More time to make use of claims and favors.
- More time to make progress in desired societies.
- More time to accumulate WoL bonuses, or to make adequate use of the costly ones (tower, maze).
- Lower loss rate of artifacts stemming from infrequent succession.
- Longer "lifespan" for strategies that depend on ruler's stats.
- On the flip-side all your tyranny penalties will stick for longer, and all who you owe favors to will have more time to make use of them.
- It's harder to take advantage of ruling heirs (giving them excess demesne, letting them accumulate their own tech points and prestige before inheriting yours)
Opinion
A ruler under ultimogeniture succession will face the following opinion modifiers:
| Character | Opinion modifier | Reason |
|---|---|---|
| Oldest child | -30 | He would certainly prefer primogeniture! |
| Youngest child | +20 | Direct benefactor of law. |
| All other children set to inherit | -20 | They would much prefer gavelkind. |
| All other dynasty members | -5 | They would prefer seniority. (Under this law, the title usually stays with ruler's branch of the dynasty.) |
Mechanic
- If a ruler has several daughters and succession is determined under agnatic-cognatic ultimogeniture, daughters with sons are ranked higher in the order of succession than daughters without sons, even if they are older.
- In the absence of eligible children, inheritance passes to collateral relatives in order of seniority of their lines of descent.
Strategies for male characters
- Stop producing heirs: once the succession is secured with a few heirs, the player can try to:
- divorce or kill spouse and remarry a woman over 45, who won't be able to bear a child.
- become
or 
. - Players with
Monks and Mystics DLC could join a Monastic Order and take the Society action to become . - If pagan, Zoroastrian or following the Eastern religions, marry only women past childbearing age and use concubines for children. Once you have a suitable heir, set all concubines aside.
- Limit legitimate heirs: Marry an older spouse.
- The window in which legitimate offspring will be produced will be relatively short, meaning that by the time the player's character reaches old age, their youngest child will more likely be an adult.
- For additional children, the player can sire bastards and selectively legitimize any that turn out well.